diff options
Diffstat (limited to 'src/leveldb/table/two_level_iterator.cc')
-rw-r--r-- | src/leveldb/table/two_level_iterator.cc | 91 |
1 files changed, 40 insertions, 51 deletions
diff --git a/src/leveldb/table/two_level_iterator.cc b/src/leveldb/table/two_level_iterator.cc index 7822ebab9c..144790dd97 100644 --- a/src/leveldb/table/two_level_iterator.cc +++ b/src/leveldb/table/two_level_iterator.cc @@ -15,38 +15,33 @@ namespace { typedef Iterator* (*BlockFunction)(void*, const ReadOptions&, const Slice&); -class TwoLevelIterator: public Iterator { +class TwoLevelIterator : public Iterator { public: - TwoLevelIterator( - Iterator* index_iter, - BlockFunction block_function, - void* arg, - const ReadOptions& options); - - virtual ~TwoLevelIterator(); - - virtual void Seek(const Slice& target); - virtual void SeekToFirst(); - virtual void SeekToLast(); - virtual void Next(); - virtual void Prev(); - - virtual bool Valid() const { - return data_iter_.Valid(); - } - virtual Slice key() const { + TwoLevelIterator(Iterator* index_iter, BlockFunction block_function, + void* arg, const ReadOptions& options); + + ~TwoLevelIterator() override; + + void Seek(const Slice& target) override; + void SeekToFirst() override; + void SeekToLast() override; + void Next() override; + void Prev() override; + + bool Valid() const override { return data_iter_.Valid(); } + Slice key() const override { assert(Valid()); return data_iter_.key(); } - virtual Slice value() const { + Slice value() const override { assert(Valid()); return data_iter_.value(); } - virtual Status status() const { + Status status() const override { // It'd be nice if status() returned a const Status& instead of a Status if (!index_iter_.status().ok()) { return index_iter_.status(); - } else if (data_iter_.iter() != NULL && !data_iter_.status().ok()) { + } else if (data_iter_.iter() != nullptr && !data_iter_.status().ok()) { return data_iter_.status(); } else { return status_; @@ -67,45 +62,41 @@ class TwoLevelIterator: public Iterator { const ReadOptions options_; Status status_; IteratorWrapper index_iter_; - IteratorWrapper data_iter_; // May be NULL - // If data_iter_ is non-NULL, then "data_block_handle_" holds the + IteratorWrapper data_iter_; // May be nullptr + // If data_iter_ is non-null, then "data_block_handle_" holds the // "index_value" passed to block_function_ to create the data_iter_. std::string data_block_handle_; }; -TwoLevelIterator::TwoLevelIterator( - Iterator* index_iter, - BlockFunction block_function, - void* arg, - const ReadOptions& options) +TwoLevelIterator::TwoLevelIterator(Iterator* index_iter, + BlockFunction block_function, void* arg, + const ReadOptions& options) : block_function_(block_function), arg_(arg), options_(options), index_iter_(index_iter), - data_iter_(NULL) { -} + data_iter_(nullptr) {} -TwoLevelIterator::~TwoLevelIterator() { -} +TwoLevelIterator::~TwoLevelIterator() = default; void TwoLevelIterator::Seek(const Slice& target) { index_iter_.Seek(target); InitDataBlock(); - if (data_iter_.iter() != NULL) data_iter_.Seek(target); + if (data_iter_.iter() != nullptr) data_iter_.Seek(target); SkipEmptyDataBlocksForward(); } void TwoLevelIterator::SeekToFirst() { index_iter_.SeekToFirst(); InitDataBlock(); - if (data_iter_.iter() != NULL) data_iter_.SeekToFirst(); + if (data_iter_.iter() != nullptr) data_iter_.SeekToFirst(); SkipEmptyDataBlocksForward(); } void TwoLevelIterator::SeekToLast() { index_iter_.SeekToLast(); InitDataBlock(); - if (data_iter_.iter() != NULL) data_iter_.SeekToLast(); + if (data_iter_.iter() != nullptr) data_iter_.SeekToLast(); SkipEmptyDataBlocksBackward(); } @@ -121,44 +112,44 @@ void TwoLevelIterator::Prev() { SkipEmptyDataBlocksBackward(); } - void TwoLevelIterator::SkipEmptyDataBlocksForward() { - while (data_iter_.iter() == NULL || !data_iter_.Valid()) { + while (data_iter_.iter() == nullptr || !data_iter_.Valid()) { // Move to next block if (!index_iter_.Valid()) { - SetDataIterator(NULL); + SetDataIterator(nullptr); return; } index_iter_.Next(); InitDataBlock(); - if (data_iter_.iter() != NULL) data_iter_.SeekToFirst(); + if (data_iter_.iter() != nullptr) data_iter_.SeekToFirst(); } } void TwoLevelIterator::SkipEmptyDataBlocksBackward() { - while (data_iter_.iter() == NULL || !data_iter_.Valid()) { + while (data_iter_.iter() == nullptr || !data_iter_.Valid()) { // Move to next block if (!index_iter_.Valid()) { - SetDataIterator(NULL); + SetDataIterator(nullptr); return; } index_iter_.Prev(); InitDataBlock(); - if (data_iter_.iter() != NULL) data_iter_.SeekToLast(); + if (data_iter_.iter() != nullptr) data_iter_.SeekToLast(); } } void TwoLevelIterator::SetDataIterator(Iterator* data_iter) { - if (data_iter_.iter() != NULL) SaveError(data_iter_.status()); + if (data_iter_.iter() != nullptr) SaveError(data_iter_.status()); data_iter_.Set(data_iter); } void TwoLevelIterator::InitDataBlock() { if (!index_iter_.Valid()) { - SetDataIterator(NULL); + SetDataIterator(nullptr); } else { Slice handle = index_iter_.value(); - if (data_iter_.iter() != NULL && handle.compare(data_block_handle_) == 0) { + if (data_iter_.iter() != nullptr && + handle.compare(data_block_handle_) == 0) { // data_iter_ is already constructed with this iterator, so // no need to change anything } else { @@ -171,11 +162,9 @@ void TwoLevelIterator::InitDataBlock() { } // namespace -Iterator* NewTwoLevelIterator( - Iterator* index_iter, - BlockFunction block_function, - void* arg, - const ReadOptions& options) { +Iterator* NewTwoLevelIterator(Iterator* index_iter, + BlockFunction block_function, void* arg, + const ReadOptions& options) { return new TwoLevelIterator(index_iter, block_function, arg, options); } |